static bool IsLastStatement(SyntaxList<StatementSyntax> statements, MultiLineIfBlockSyntax ifBlock)
{
return statements.IndexOf(ifBlock) + 1 >= statements.Count;
}
static IEnumerable<SyntaxNode> GetStatements(MultiLineIfBlockSyntax ifBlock)
{
foreach (var stmt in ifBlock.Statements)
yield return stmt.WithAdditionalAnnotations(Formatter.Annotation);
}
static IEnumerable<SyntaxNode> GenerateNewScript(MultiLineIfBlockSyntax ifBlock)
{
var ifStatement = GenerateInvertedIfStatement(ifBlock.IfStatement);
yield return SyntaxFactory.MultiLineIfBlock(ifStatement)
.WithStatements(GenerateNewTrueStatement(ifBlock.ElseBlock.Statements))
.WithLeadingTrivia(ifBlock.GetLeadingTrivia())
.WithTrailingTrivia(ifBlock.GetTrailingTrivia())
.WithAdditionalAnnotations(Formatter.Annotation);
foreach (var stmt in ifBlock.Statements)
{
yield return stmt.WithAdditionalAnnotations(Formatter.Annotation);
}
}
internal static bool CollectCaseBlocks(List<CaseBlockSyntax> result, SemanticModel context, MultiLineIfBlockSyntax ifBlock, ExpressionSyntax switchExpr)
{
// if
var labels = new List<CaseClauseSyntax>();
if (!CollectCaseLabels(labels, context, ifBlock.IfStatement.Condition, switchExpr))
return false;
result.Add(SyntaxFactory.CaseBlock(SyntaxFactory.CaseStatement(labels.ToArray()), ifBlock.Statements));
foreach (var block in ifBlock.ElseIfBlocks)
{
labels = new List<CaseClauseSyntax>();
if (!CollectCaseLabels(labels, context, block.ElseIfStatement.Condition, switchExpr))
return false;
result.Add(SyntaxFactory.CaseBlock(SyntaxFactory.CaseStatement(labels.ToArray()), block.Statements));
}
// else
if (ifBlock.ElseBlock != null) {
result.Add(SyntaxFactory.CaseElseBlock(SyntaxFactory.CaseElseStatement(SyntaxFactory.ElseCaseClause()), ifBlock.ElseBlock.Statements));
}
return true;
}
private Decisions TraverseMultiIfStatement(MultiLineIfBlockSyntax mlib, ref int returnCnt, bool nested = false)
{
Decisions retDecisions = new Decisions();
foreach (SyntaxNode sn in mlib.ChildNodes())
{
if (sn is IfPartSyntax)
{
retDecisions.IfStatements.Add(TraverseIfStatement(sn as IfPartSyntax, ref returnCnt, nested));
}
else if (sn is ElsePartSyntax)
{
retDecisions.ElseStatements.Add(TraverseElseStatement(sn as ElsePartSyntax, ref returnCnt, nested));
}
}
return retDecisions;
}
public override void VisitMultiLineIfBlock(MultiLineIfBlockSyntax node) => counter.CheckNesting(node.IfStatement.IfKeyword, () => base.VisitMultiLineIfBlock(node));
public override async Task ComputeRefactoringsAsync(CodeRefactoringContext context)
{
var document = context.Document;
if (document.Project.Solution.Workspace.Kind == WorkspaceKind.MiscellaneousFiles)
{
return;
}
var span = context.Span;
if (!span.IsEmpty)
{
return;
}
var cancellationToken = context.CancellationToken;
if (cancellationToken.IsCancellationRequested)
{
return;
}
var model = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
if (model.IsFromGeneratedCode(cancellationToken))
{
return;
}
var root = await model.SyntaxTree.GetRootAsync(cancellationToken).ConfigureAwait(false);
var selectStatement = root.FindNode(span) as SelectStatementSyntax;
if (selectStatement == null)
{
return;
}
var node = selectStatement.Parent as SelectBlockSyntax;
if (node == null || node.CaseBlocks.Count == 0)
{
return;
}
if (node.CaseBlocks.Count == 1 && node.CaseBlocks[0].CaseStatement.Cases.OfType <ElseCaseClauseSyntax>().Any())
{
return;
}
foreach (var block in node.CaseBlocks)
{
var lastStatement = block.Statements.LastOrDefault() as ExitStatementSyntax;
if (HasNonTrailingExitSelects(block, lastStatement != null && lastStatement.BlockKeyword.IsKind(SyntaxKind.SelectKeyword) ? lastStatement : null))
{
return;
}
}
context.RegisterRefactoring(
CodeActionFactory.Create(
span,
DiagnosticSeverity.Info,
GettextCatalog.GetString("To 'if'"),
t2 =>
{
MultiLineIfBlockSyntax ifBlock = null;
List <ElseIfBlockSyntax> elseIfs = new List <ElseIfBlockSyntax>();
ElseBlockSyntax defaultElse = null;
foreach (var block in node.CaseBlocks)
{
var condition = CollectCondition(node.SelectStatement.Expression, block.CaseStatement.Cases.ToArray());
var statements = block.Statements;
var lastStatement = block.Statements.LastOrDefault() as ExitStatementSyntax;
if (lastStatement != null && lastStatement.BlockKeyword.IsKind(SyntaxKind.SelectKeyword))
{
statements = SyntaxFactory.List(statements.Take(statements.Count - 1));
}
if (condition == null)
{
defaultElse = SyntaxFactory.ElseBlock()
.AddStatements(statements.ToArray())
.WithLeadingTrivia(block.GetLeadingTrivia())
.WithTrailingTrivia(block.GetTrailingTrivia());
break;
}
else if (ifBlock == null)
{
ifBlock = SyntaxFactory.MultiLineIfBlock(SyntaxFactory.IfStatement(condition).WithThenKeyword(SyntaxFactory.Token(SyntaxKind.ThenKeyword)))
.WithStatements(statements);
}
else
{
elseIfs.Add(SyntaxFactory.ElseIfBlock(SyntaxFactory.ElseIfStatement(condition).WithThenKeyword(SyntaxFactory.Token(SyntaxKind.ThenKeyword)), statements));
}
}
ifBlock = ifBlock.WithElseIfBlocks(SyntaxFactory.List(elseIfs));
if (defaultElse != null)
{
ifBlock = ifBlock.WithElseBlock(defaultElse);
}
ifBlock = ifBlock.WithLeadingTrivia(node.GetLeadingTrivia().Concat(ifBlock.GetLeadingTrivia())).WithTrailingTrivia(node.GetTrailingTrivia())
.WithElseBlock(defaultElse).WithAdditionalAnnotations(Formatter.Annotation);
return(Task.FromResult(document.WithSyntaxRoot(root.ReplaceNode(node, ifBlock))));
})
);
}